Evaluating the impact of malaria rapid diagnostic tests on patient-important outcomes in sub-Saharan Africa: a systematic review of study methods to guide effective implementation.

Objective: To perform critical methodological assessments on designs, outcomes, quality and implementation limitations of studies evaluating the impact of malaria rapid diagnostic tests (mRDTs) on patient-important outcomes in sub-Saharan Africa.

Design: A systematic review of study methods.

Data Sources: MEDLINE, EMBASE, Cochrane Library, African Index Medicus and clinical trial registries were searched up to May 2022.

Eligibility Criteria: Primary quantitative studies that compared mRDTs to alternative diagnostic tests for malaria on patient-important outcomes within sub-Sahara Africa.

Data Extraction And Synthesis: Studies were sought by an information specialist and two independent reviewers screened for eligible records and extracted data using a predesigned form using Covidence. Methodological quality was assessed using the National Institutes of Health tools. Descriptive statistics and thematic analysis guided by the Supporting the Use of Research Evidence framework were used for analysis. Findings were presented narratively, graphically and by quality ratings.

Results: Our search yielded 4717 studies, of which we included 24 quantitative studies; (15, 62.5%) experimental, (5, 20.8%) quasi-experimental and (4, 16.7%) observational studies. Most studies (17, 70.8%) were conducted within government-owned facilities. Of the 24 included studies, (21, 87.5%) measured the therapeutic impact of mRDTs. Prescription patterns were the most reported outcome (20, 83.3%). Only (13, 54.2%) of all studies reported statistically significant findings, in which (11, 45.8%) demonstrated mRDTs' potential to reduce over-prescription of antimalarials. Most studies (17, 70.8%) were of good methodological quality; however, reporting sample size justification needs improvement. Implementation limitations reported were mostly about health system constraints, the unacceptability of the test by the patients and low trust among health providers.

Conclusion: Impact evaluations of mRDTs in sub-Saharan Africa are mostly randomised trials measuring mRDTs' effect on therapeutic outcomes in real-life settings. Though their methodological quality remains good, process evaluations can be incorporated to assess how contextual concerns influence their interpretation and implementation.

Prospero Registration Number: CRD42018083816.